Plug for a bathtub



FIG. 1 is a top, perspective view of a bathtub plug for drains of the claimed design;

FIG. 2 is a bottom, perspective view of the bathtub plug of FIG. 1;

FIG. 3 is a top view of the bathtub plug of FIG. 1;

FIG. 4 is a bottom view of the bathtub plug of FIG. 1;

FIG. 5 is a side view of the bathtub plug of FIG. 1; and,

FIG. 6 is another side view of the bathtub plug of FIG. 1 (with the bathtub plug being rotated by 90-degrees relative to its position in FIG. 5). 

I claim the ornamental design for a plug for a bathtub, as shown and described. 